package com.net.xpay.operator.secutiry;

import com.net.xpay.core.helper.DomainHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.session.web.http.CookieSerializer;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.Base64;
import java.util.List;
import java.util.regex.Pattern;

/**
 * @author  on 2018/9/11.
 * 从DefaultCookieSerializer复制过来
 * @see org.springframework.session.web.http.DefaultCookieSerializer
 * 主要是添加了支持不同的domainName(从request的domain parse出来）
 */
public class CustomDomainNameCookieSerializer implements CookieSerializer {

    private static final Logger LOGGER = LoggerFactory.getLogger(CustomDomainNameCookieSerializer.class);

    private DomainHelper domainHelper; //外部注入的

    private String cookieName = "SESSION";

    private Boolean useSecureCookie;

    private boolean useHttpOnlyCookie = true;

    private String cookiePath;

    private Integer cookieMaxAge;

    private String domainName;

    private Pattern domainNamePattern;

    private String jvmRoute;

    private boolean useBase64Encoding = true;

    private String rememberMeRequestAttribute;

    /*
     * (non-Javadoc)
     *
     * @see org.springframework.session.web.http.CookieSerializer#readCookieValues(javax.
     * servlet.http.HttpServletRequest)
     */
    @Override
    public List<String> readCookieValues(HttpServletRequest request) {
        Cookie[] cookies = request.getCookies();
        List<String> matchingCookieValues = new ArrayList<>();
        if (cookies != null) {
            for (Cookie cookie : cookies) {
                if (this.cookieName.equals(cookie.getName())) {
                    String sessionId = (this.useBase64Encoding
                            ? base64Decode(cookie.getValue()) : cookie.getValue());
                    if (sessionId == null) {
                        continue;
                    }
                    if (this.jvmRoute != null && sessionId.endsWith(this.jvmRoute)) {
                        sessionId = sessionId.substring(0,
                                sessionId.length() - this.jvmRoute.length());
                    }
                    matchingCookieValues.add(sessionId);
                }
            }
        }
        return matchingCookieValues;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.springframework.session.web.http.CookieWriter#writeCookieValue(org.
     * springframework.session.web.http.CookieWriter.CookieValue)
     */
    @Override
    public void writeCookieValue(CookieValue cookieValue) {
        HttpServletRequest request = cookieValue.getRequest();
        HttpServletResponse response = cookieValue.getResponse();

        String requestedCookieValue = cookieValue.getCookieValue();
        String actualCookieValue = (this.jvmRoute != null
                ? requestedCookieValue + this.jvmRoute : requestedCookieValue);

        Cookie sessionCookie = new Cookie(this.cookieName, this.useBase64Encoding
                ? base64Encode(actualCookieValue) : actualCookieValue);
        sessionCookie.setSecure(isSecureCookie(request));
        sessionCookie.setPath(getCookiePath(request));
        String domainName = getDomainName(request);
        if (domainName != null) {
            sessionCookie.setDomain(domainName);
        }

        if (this.useHttpOnlyCookie) {
            sessionCookie.setHttpOnly(true);
        }

        if (cookieValue.getCookieMaxAge() < 0) {
            if (this.rememberMeRequestAttribute != null
                    && request.getAttribute(this.rememberMeRequestAttribute) != null) {
                // the cookie is only written at time of session creation, so we rely on
                // session expiration rather than cookie expiration if remember me is enabled
                cookieValue.setCookieMaxAge(Integer.MAX_VALUE);
            } else if (this.cookieMaxAge != null) {
                cookieValue.setCookieMaxAge(this.cookieMaxAge);
            }
        }
        sessionCookie.setMaxAge(cookieValue.getCookieMaxAge());

        response.addCookie(sessionCookie);
    }

    /**
     * Decode the value using Base64.
     *
     * @param base64Value the Base64 String to decode
     * @return the Base64 decoded value
     * @since 1.2.2
     */
    private String base64Decode(String base64Value) {
        try {
            byte[] decodedCookieBytes = Base64.getDecoder().decode(base64Value);
            return new String(decodedCookieBytes);
        } catch (Exception ex) {
            LOGGER.debug("Unable to Base64 decode value: " + base64Value);
            return null;
        }
    }

    /**
     * Encode the value using Base64.
     *
     * @param value the String to Base64 encode
     * @return the Base64 encoded value
     * @since 1.2.2
     */
    private String base64Encode(String value) {
        byte[] encodedCookieBytes = Base64.getEncoder().encode(value.getBytes());
        return new String(encodedCookieBytes);
    }

    /**
     * Sets if a Cookie marked as secure should be used. The default is to use the value
     * of {@link HttpServletRequest#isSecure()}.
     *
     * @param useSecureCookie determines if the cookie should be marked as secure.
     */
    public void setUseSecureCookie(boolean useSecureCookie) {
        this.useSecureCookie = useSecureCookie;
    }

    /**
     * Sets if a Cookie marked as HTTP Only should be used. The default is true.
     *
     * @param useHttpOnlyCookie determines if the cookie should be marked as HTTP Only.
     */
    public void setUseHttpOnlyCookie(boolean useHttpOnlyCookie) {
        this.useHttpOnlyCookie = useHttpOnlyCookie;
    }

    private boolean isSecureCookie(HttpServletRequest request) {
        if (this.useSecureCookie == null) {
            return request.isSecure();
        }
        return this.useSecureCookie;
    }

    /**
     * Sets the path of the Cookie. The default is to use the context path from the
     * {@link HttpServletRequest}.
     *
     * @param cookiePath the path of the Cookie. If null, the default of the context path
     *                   will be used.
     */
    public void setCookiePath(String cookiePath) {
        this.cookiePath = cookiePath;
    }

    public void setCookieName(String cookieName) {
        if (cookieName == null) {
            throw new IllegalArgumentException("cookieName cannot be null");
        }
        this.cookieName = cookieName;
    }

    /**
     * Sets the maxAge property of the Cookie. The default is to delete the cookie when
     * the browser is closed.
     *
     * @param cookieMaxAge the maxAge property of the Cookie
     */
    public void setCookieMaxAge(int cookieMaxAge) {
        this.cookieMaxAge = cookieMaxAge;
    }

    /**
     * Sets an explicit Domain Name. This allow the domain of "example.com" to be used
     * when the request comes from www.example.com. This allows for sharing the cookie
     * across sub-domains. The default is to use the current domain.
     *
     * @param domainName the name of the domain to use. (i.e. "example.com")
     * @throws IllegalStateException if the domainNamePattern is also set
     */
    public void setDomainName(String domainName) {
        if (this.domainNamePattern != null) {
            throw new IllegalStateException(
                    "Cannot set both domainName and domainNamePattern");
        }
        this.domainName = domainName;
    }

    /**
     * <p>
     * Sets a case insensitive pattern used to extract the domain name from the
     * {@link HttpServletRequest#getServerName()}. The pattern should provide a single
     * grouping that defines what the value is that should be matched. User's should be
     * careful not to output malicious characters like new lines to prevent from things
     * like <a href= "https://www.owasp.org/index.php/HTTP_Response_Splitting">HTTP
     * Response Splitting</a>.
     * </p>
     * <p>
     * <p>
     * If the pattern does not match, then no domain will be set. This is useful to ensure
     * the domain is not set during development when localhost might be used.
     * </p>
     * <p>
     * An example value might be "^.+?\\.(\\w+\\.[a-z]+)$". For the given input, it would
     * provide the following explicit domain (null means no domain name is set):
     * </p>
     * <p>
     * <ul>
     * <li>example.com - null</li>
     * <li>child.sub.example.com - example.com</li>
     * <li>localhost - null</li>
     * <li>127.0.1.1 - null</li>
     * </ul>
     *
     * @param domainNamePattern the case insensitive pattern to extract the domain name
     *                          with
     * @throws IllegalStateException if the domainName is also set
     */
    public void setDomainNamePattern(String domainNamePattern) {
        if (this.domainName == null) {
            this.domainNamePattern = null;
        } else {
            this.domainNamePattern = Pattern.compile(domainNamePattern,
                    Pattern.CASE_INSENSITIVE);
        }
    }

    /**
     * <p>
     * Used to identify which JVM to route to for session affinity. With some
     * implementations (i.e. Redis) this provides no performance benefit. However, this
     * can help with tracing logs of a particular user. This will ensure that the value of
     * the cookie is formatted as
     * </p>
     * <code>
     * sessionId + "." jvmRoute
     * </code>
     * <p>
     * To use set a custom route on each JVM instance and setup a frontend proxy to
     * forward all requests to the JVM based on the route.
     * </p>
     *
     * @param jvmRoute the JVM Route to use (i.e. "node01jvmA", "n01ja", etc)
     */
    public void setJvmRoute(String jvmRoute) {
        this.jvmRoute = "." + jvmRoute;
    }

    /**
     * Set if the Base64 encoding of cookie value should be used. This is valuable in
     * order to support <a href="https://tools.ietf.org/html/rfc6265">RFC 6265</a> which
     * recommends using Base 64 encoding to the cookie value.
     *
     * @param useBase64Encoding the flag to indicate whether to use Base64 encoding
     */
    public void setUseBase64Encoding(boolean useBase64Encoding) {
        this.useBase64Encoding = useBase64Encoding;
    }

    /**
     * Set the request attribute name that indicates remember-me login. If specified, the
     * cookie will be written as Integer.MAX_VALUE.
     *
     * @param rememberMeRequestAttribute the remember-me request attribute name
     * @since 1.3.0
     */
    public void setRememberMeRequestAttribute(String rememberMeRequestAttribute) {
        this.rememberMeRequestAttribute = rememberMeRequestAttribute;
    }

    private String getDomainName(HttpServletRequest request) {
        if (this.domainName != null) {
            return this.domainName;
        }
        //唯一修改的地方
        return domainHelper.getCookieDomain(request);
    }

    private String getCookiePath(HttpServletRequest request) {
        if (this.cookiePath == null) {
            return request.getContextPath() + "/";
        }
        return this.cookiePath;
    }

    public void setDomainHelper(DomainHelper domainHelper) {
        this.domainHelper = domainHelper;
    }
}
